{
    "tag": 20159,
    "title": "Dataset of rise velocities for gas bubbles with and without gas hydrate shells",
    "pubdate": "20260302",
    "sername": null,
    "series_name": null,
    "issue": "DOI:10.5066\/P9IG5BHE",
    "publish": null,
    "publisher_name": null,
    "onlink": "https:\/\/cmgds.marine.usgs.gov\/catalog\/whcmsc\/SB_data_release\/DR_P9IG5BHE\/Flow_Loop_Rise_Velocity_Metadata.faq.html",
    "format": null,
    "email": null,
    "descript": "Methane gas bubbles emitted from the seafloor transport methane through the water column. Methane transport is important to track because of the substantial role methane plays in biological processes and in the Earth\u2019s climate system. Existing models used to predict methane transport based on methane dissolution rates from rising bubbles generally estimate bubble rise velocity from the bubble\u2019s volume. This standard theoretical approach relies on equations that parameterize the dynamic interaction between volume, shape, and rise velocity for flexible-walled bubbles. These equations hold for bubbles rising in pure water, but when gas bubbles are emitted from sediment at water depths exceeding ~300-500 meters, the combination of elevated pressure and low bottom water temperatures can lead to a solid gas hydrate forming on the bubble surface. The solid gas-hydrate coating can create a rigid bubble surface, which prevents the usual dynamic interaction between bubble volume, shape and rise velocity and reduces the bubble\u2019s rise velocity. To better understand how a hydrate coating on the bubble surface affects the bubble\u2019s rise velocity, the U.S. Geological Survey conducted controlled laboratory experiments in which calibrated, high-speed imagery was used to measure the rise velocity of individual hydrate-free and hydrate-coated gas bubbles. Xenon was the hydrate-forming gas used because xenon hydrate has the same structure as methane hydrate, but forms at low enough pressures that rise-velocity experiments can be run in transparent acrylic cylinders. Estimates of the equivalent diameter, de, which is the diameter of a spherical bubble with the same volume as the observed bubble, ranged from 0.8 to 12 millimeters (mm), whereas the aspect ratio (major axis length divided by minor axis length) of the generated gas bubbles ranged from 1.04 to 2.17 mm. The rise-velocity data show that hydrate-coated gas bubbles generally rise slower than hydrate-free bubbles of the same volume. For hydrate-coated bubbles with de between 4\u20137 mm, the average rise velocity is 19.8 centimeters per second (cm\/s) or 10 percent slower than hydrate-free bubbles of the same volume. Rise velocities for hydrate-free and hydrate-coated bubbles also diverge as the aspect ratio increases. For hydrate-free bubbles, the rise velocity increases with increasing aspect ratio, as is anticipated for bubbles in clean systems (bubbles with flexible interfaces). In contrast, hydrate-coated bubble rise velocities decrease as their aspect ratio increases. Measurable differences between hydrate-free and hydrate-coated bubble rise velocities indicate that the existing clean-bubble rise velocity parameterizations currently used in methane dissolution modelling need to be carefully examined before they are used to predict the bubble rise behavior of rigid, hydrate-coated bubbles.",
    "lang": null,
    "journal": null,
    "pwid": null,
    "originator": [
        {
            "name": "Padilla, Alexandra M.",
            "role": "Author"
        },
        {
            "name": "Waite, William F.",
            "role": "Author"
        }
    ],
    "index_term": [
        {
            "thcode": 2,
            "code": "427",
            "name": "gas hydrate resources",
            "scope": "Deposits of a crystalline solid in which water molecules trap gas molecules, usually methane, in a cagelike structure known as a clathrate occurring in sediments overlain by cold deep water."
        },
        {
            "thcode": 2,
            "code": "506",
            "name": "greenhouse gases",
            "scope": "Atmospheric gases, including carbon dioxide, fluorocarbons, methane, nitrous oxide, sulfur hexafluoride, ozone, and water vapor, that trap radiant (infrared) energy keeping the earth's surface warmer than it would otherwise be."
        },
        {
            "thcode": 2,
            "code": "2088",
            "name": "laboratory experiments",
            "scope": "Procedures carried out in a laboratory under controlled conditions to test specific scientific hypotheses."
        },
        {
            "thcode": 2,
            "code": "707",
            "name": "marine geophysics",
            "scope": "Branch of earth sciences concerned with the physical processes of the oceans and continental margins.  We include here studies of large bodies of brackish and fresh water, such as lakes and rivers."
        },
        {
            "thcode": 2,
            "code": "1525",
            "name": "noble gas elements",
            "scope": null
        },
        {
            "thcode": 2,
            "code": "818",
            "name": "ocean sciences",
            "scope": "Sciences involved in the study of geological, biological, chemical, and physical characteristics and processes of the oceans."
        },
        {
            "thcode": 2,
            "code": "1613",
            "name": "xenon",
            "scope": "Noble gas element with symbol Xe and atomic number 54 <http:\/\/periodic.lanl.gov\/54.shtml>"
        },
        {
            "thcode": 15,
            "code": "008",
            "name": "geoscientificInformation",
            "scope": "Information pertaining to earth sciences, for example geophysical features and processes, geology, minerals, sciences dealing with the composition, structure and origin of the earth's rocks, risks of earthquakes, volcanic activity, landslides, gravity information, soils, permafrost, hydrogeology, groundwater, erosion"
        },
        {
            "thcode": 15,
            "code": "014",
            "name": "oceans",
            "scope": "Features and characteristics of salt water bodies (excluding inland waters), for example tides, tidal waves, coastal information, reefs, maritime, outer continental shelf submerged lands, shoreline"
        }
    ],
    "place_term": [],
    "image": [
        {
            "name": "https:\/\/www.sciencebase.gov\/catalog\/file\/get\/63249633d34e71c6d67b570f?name=Flow_Loop_Coordinates_BrowseGraphic.png&allowOpen=true",
            "description": "Flow loop chamber schematic with an overlay of the measured rise path of a xenon hydrate-coated bubble. The dual high-speed cameras capture the bubble position and shape as the bubble rises. The bubble volume, aspect ratio, rise path and rise velocity can all be calculated from these images and the known camera frame rate. Bubble coordinates are in millimeters."
        }
    ],
    "fan": []
}